The role of a trickster god is usually to deceive or trick the other gods in order to help us mortals.

In greek mythology, Prometheus gave us fire, In polynesian mythology Maui raised the Hawai'i Islands. In the Ainu religion there is a mountain god (who is a bear) who is about to destroy all human life, but a fox god (the trickster) tricks him into thinking that they are not to blame (I think, I cannot remember exactly why he forgave us).